B D Finch (asker) Mar 16, 2020:

@writeaway Yes, you guessed right.

writeaway Mar 16, 2020:

Thank you for letting us know the answer from the extremely reliable expert Bourth. Yes, he is sorely missed. (Correct me if it's not him).

B D Finch (asker) Mar 16, 2020:

Answer supplied by A N Other I have just received the answer to this from a much-missed former contributor to KudoZ. So, no points but I have put in a KOG entry.

Daryo Mar 15, 2020:

Not a cynic, just realist ... "Le comportement de la réaction au feu ne diminue pas avec le temps". (Call me a cynic, but I find that hard to believe.)

If you are buying for yourself "cynic" would be the wrong word ... Protecting yourself from the dangers of marketing BS would be closer to the mark.

https://fr.wikipedia.org/wiki/Incendie_du_5-7
http://www.leparisien.fr/faits-divers/l-incendie-du-5-7-la-n...

I remember why the decoration started burning so quickly - it was bought second-hand from TV studios who had to discard it because the flame retardant incorporated in it was guaranteed to be effective only for a specified number of months/years and the foam was past its "use it safely" date. It was another case of some property / characteristic of a material "persisting" (?) "being preserved" (?) for only a limited period of time.

Have you tried to find Safety data sheets from UK manufacturers of same/similar material?

like these https://www.knaufinsulation.co.uk/downloads/safety-datasheet...

You could OTOH call me a cynic as I really don't see why you felt the need to say this "I am not interested in guesses, Google trawls (I can do that myself) .."

philgoddard Mar 14, 2020:

The fact that it's insulation material is essential context. In that case, "durability of thermal resistance" seems fine to me.

writeaway Mar 14, 2020:

Is the word sustainability taboo in this context???

B D Finch (asker) Mar 14, 2020:

@Libby It's not reliability, insofar as the material can be absolutely relied upon to break down over time. The question is what phrase would be used in English for this item on a product data sheet. The results cell entry for this is the rather unhelpful "Voir tableau du dop", which might possibly be slightly useful if I had the DoP table as it would at least give the units of measurement, but I don't have it. The preceding item on the data sheet of a related product is "Durabilité de la réaction au feu, vieillissement / dégradation" and the result given there is "Le comportement de la réaction au feu ne diminue pas avec le temps". (Call me a cynic, but I find that hard to believe.)

B D Finch (asker) Mar 14, 2020:

What it means There is no further context provided in my text. However, I am 99.9% certain that what it means is how the insulation material behaves, i.e. how it loses its thermal resistance properties over time:. To give an example, if you have glass fibre or rockwool insulation on the floor of your attic, after a few years it starts to deteriorate, the fibres break down and start to turn to dust. As this happens, the insulating efficiency also deteriorates. Here's some info on how the insulation material I'm concerned with in my text also breaks down over time in a slightly different way from rockwool: https://www.sciencedirect.com/science/article/pii/S014139101... (In the light of that, I don't mind that my house rests on a totally uninsulated slab, especially as the floor somehow never seems to get very cold.)

Libby Cohen Mar 14, 2020:

Possibly reliability (if focus is on materials) Hi BD. Would you be able to share a bit more about the context? It may be about the reliability of the thermal resistance (materials) involved. Thanks.